Hepatitis A

Hepatitis A or infectious jaundice is caused by a picornavirus transmitted by the fecal-oral route, often associated with ingestion of contaminated food or with anal/oral sex. It causes an acute form of hepatitis and does not have a chronic stage. The patient's immune system makes antibodies against hepatitis A that confer immunity against future infection. People with hepatitis A are advised to rest, stay hydrated and avoid alcohol. A vaccine is available that will prevent infection from hepatitis A for life. Hepatitis A can be spread through personal contact, consumption of raw sea food or drinking contaminated water. This occurs primarily in third world countries. Strict personal hygiene and the avoidance of raw and unpeeled foods can help prevent an infection. Infected people excrete the hepatitis A virus with their feces two weeks before and one week after the appearance of jaundice. The time between the infection and the start of the illness averages 28 days (ranging from 15 to 50 days),[1] and most recover fully within 2 months, although approximately 15% of sufferers may experience continuous or relapsing symptoms from six months to a year following initial diagnosis.[2]

Hepatitis C

Hepatitis C (originally "non-A non-B hepatitis") is caused by a virus with an RNAgenome that is a member of the Flaviviridae family. It can be transmitted through contact with blood (including through sexual contact where the two parties' blood is mixed) and can also cross the placenta. Hepatitis C may lead to a chronic form of hepatitis, culminating in cirrhosis. It can remain asymptomatic for 10-20 years. Patients with hepatitis C are susceptible to severe hepatitis if they contract either hepatitis A or B, so all hepatitis C patients should be immunized against hepatitis A and hepatitis B if they are not already immune, and avoid alcohol. The virus can cause cirrhosis of the liver. HCVviral levels can be reduced to undetectable levels by a combination of interferon and the antiviral drugribavirin. The genotype of the virus determines the rate of response to this treatment regimen. Genotype 1 is more resistant to interferon therapy than other HCV genotypes.

Hepatitis D

Hepatitis D is caused by hepatitis delta agent, which is similar to a viroid as it can only propagate in the presence of the Hepatitis B virus.

Hepatitis E

Hepatitis E produces symptoms similar to hepatitis A, although it can take a fulminant course in some patients, particularly pregnantwomen; it is more prevalent in the Indian subcontinent.

Hepatitis F virus

Hepatitis G, or GBV-C

Another potential viral cause of hepatitis, hepatitis G virus, has been identified,[3] and is probably spread by blood and sexual contact.[4] There is, however, doubt about whether it causes hepatitis, or is just associated with hepatitis, as it does not appear to replicate primarily in the liver.[5] It is now classified as GBV-C.

The clinical course of drug-induced hepatitis is quite variable, depending on the drug and the patient's tendency to react to the drug. For example, halothane hepatitis can range from mild to fatal as can INH-induced hepatitis. Hormonal contraception can cause structural changes in the liver. Amiodarone hepatitis can be untreatable since the long half life of the drug (up to 60 days) means that there is no effective way to stop exposure to the drug. Statins can cause elevations of liver functionblood tests normally without indicating an underlying hepatitis. Lastly, human variability is such that any drug can be a cause of hepatitis.

Metabolic Disorders

Obstructive

Obstructive jaundice is the term used to describe jaundice due to obstruction of the bile duct (by gallstones or external obstruction by cancer). If longstanding, it leads to destruction and inflammation of liver tissue.